1. ATOMS NOTES
Adapted from

4. Subatomic Particles Name Charge Location Mass Proton (p) Positive +
nucleus
1 amu
Neutron
(n)
Neutral
Electron
(e-)
Negative -
Electron cloud
.0018 amu

5. Atomic Mass Unit (amu)
SI (International System of Unit) unit for subatomic particles’ mass
Mass of 1 proton = 1.7 x grams
Mass of e- = mass of 1 p

6. Nucleus Small, dense center of an atom Contains protons & neutrons
Has an overall positive charge
Contains most of the atom’s mass

7. ELEMENT “FACE” 6 C Carbon 12
Shows info about an element on periodic table 6 C
Carbon 12

8. Atomic Number
(# of protons)
(# of electrons) 6 C
Carbon 12

9. C 6 Carbon 12 Atomic Number Element Symbol (# of protons)
(# of electrons) 6 C
Carbon 12
Element Symbol

10. C 6 Carbon 12 Atomic Number Element Symbol Element Name (# of protons)
(# of electrons) 6 C
Carbon 12
Element Symbol
Element Name

11. C 6 Carbon 12 Atomic Number Element Symbol Element Name Atomic Mass
(# of protons)
(# of electrons) 6 C
Carbon 12
Element Symbol
Element Name
Atomic Mass
(#of protons # of neutrons)

12. Electrons Travel in regions of space around the nucleus
(electron cloud, energy levels, orbitals)
Valence Electrons
In outermost energy level
Play important role in chemical reactions
Energy Level
# of e-
1st 2
2nd 8
3rd 18

13. Atomic Mass #p + #n
Atomic Number - #p
# of neutrons #n

14. Carbon e- 6p 6n e- e- e- e- e-